---
id: "hardman-a-primer-on-keri-acdcs-and-cesr"
type: "paper"
type_label: "Papers and paper collections"
title: "A Primer on KERI, ACDCs, and CESR"
maintainer: "Daniel Hardman"
authors:
  - "Daniel Hardman"
date: "2025-12-19"
year: 2025
reading_level: "practitioner"
reading_level_label: "Practitioner"
reading_level_meaning: "architects, product people and adopters who know identity systems"
evidence: "informative"
evidence_meaning: "an author's paper, deck, tutorial or post explaining the suite"
status: "active"
status_meaning: "changed within the last six months, or a live service"
access: "public"
access_meaning: "anyone with the link"
topics:
  - "start-here"
  - "theory"
  - "cryptography"
roles:
  - "developer"
  - "security-architect"
  - "product"
  - "communications"
  - "researcher"
source_url: "https://dhh1128.github.io/papers/keri-primer.html"
source_license: null
source_license_note: null
found_on: "hardman-papers"
kerisse_credit: false
abstract_license: "CC BY 4.0"
abstract_license_url: "https://creativecommons.org/licenses/by/4.0/"
abstract_attribution: "KSKB, the KERISuite Knowledge Base (https://kskb.dev/)"
last_checked: "2026-10-15"
kskb_url: "https://kskb.dev/cards/hardman-a-primer-on-keri-acdcs-and-cesr/"
kskb_app_url: "https://kskb.dev/#item/hardman-a-primer-on-keri-acdcs-and-cesr"
kskb_record_url: "https://kskb.dev/data/kskb/resources/hardman-a-primer-on-keri-acdcs-and-cesr"
kskb_markdown_url: "https://kskb.dev/export/cards/hardman-a-primer-on-keri-acdcs-and-cesr.md"
---

# A Primer on KERI, ACDCs, and CESR

An introductory paper by Daniel Hardman that explains the three layers of the KERI suite: Key Event Receipt Infrastructure (KERI) for identifiers and key state, Authentic Chained Data Containers (ACDCs) for verifiable data, and Composable Event Streaming Representation (CESR) for encoding. It starts from the weaknesses of administrative public key infrastructure (PKI) and walks through each layer's mechanisms with worked examples. Written for engineers and technically literate readers new to the suite.

Labels: reading level Practitioner; evidence informative (an author's paper, deck, tutorial or post explaining the suite).
Source: https://dhh1128.github.io/papers/keri-primer.html (license not recorded).
The abstract is KSKB's own text under Creative Commons Attribution 4.0 (CC BY 4.0), https://creativecommons.org/licenses/by/4.0/; credit KSKB, the KERISuite Knowledge Base (https://kskb.dev/).